This invention relates to article dispensing and feeding, especially equipment for automatically feeding elongated stackable workpieces or other articles, particularly elongated articles, such as boards, having opposed planar sides in the longitudinal direction and a width across the planar sides transverse to the longitudinal direction that is at least as great as, and typically more than two times greater than, the thickness between the planar sides. These dispensers and feeders are particularly adapted for such articles to a workstation or site where they will undergo assembly or other operations.
Mechanical dispensers and feeders of elongated articles are desirable, particularly for feeding workpieces to a workstation, in order to avoid the expense of additional operators for feeding the articles individually by hand. However, typical mechanical feeders are only capable of moving elongated articles individually from one location to another, without any capability for consecutive feeding to a workstation, selectively, of workpieces of differing configurations or types in a desired order or to feed elongated articles oriented with their longitudinal dimension transverse to the path of travel to a selected lateral placement at the workstation.
For some operations feeding of elongated workpieces to a precise lateral placement at a workstation is essential. Additionally, it may be a requirement that workpieces having a variety of configurations or types be fed selectively and in sequence to the workstation. A typical workstation that would benefit from such a feeding device is described in U.S. Pat. No. 5,222,290 (Patent ""290), which concerts a machine for automatically applying hinges to doors and door jambs. As described in Patent ""290, the jamb is placed and held in a workstation along side the side edge of the door end for application of hinges connecting the jamb and the door edge by tools mounted on carriages that move longitudinally along the jamb and door edge. It is important that a jamb of appropriate configuration be fed to the workstation for each assembly operation, and particularly a jamb configured for a left side opening door or a jamb configured for a right side opening door. It is also important that jambs be fed to the precise longitudinal location at the workstation for proper assembly with the door and that location and that location may be different for jambs of different configuration, e.g. for a left opening or for a right opening door. Door jambs, the two side members of a door frame, will typically have a recess or notch along one longitudinal side for receiving a door edge and a notch at the top end for mating with the end edge of a horizontal sill extending between the left and right side jambs. The jamb for either a left or right-opening door is placed in the workstation with its notched longitudinal side facing in the direction of the hinge applying equipment. To place a jamb for a left-opening door in the workstation with this orientation of its notched longitudinal side, its notched top will have to be at the opposite end from that for a right-opening door placed in the workstation for this same orientation. Thus, a workstation for assembly of both left and right-opening door and frame units will need to be selectively fed door jambs configured for either left or right-side opening doors and feed them with their tops at opposite ends of the workstation. Also, the left and right-side opening jambs will need to be selectively fed to different longitudinal locations at the workstation in order to carry out the assembly operations, e.g. routing and hinge application by stationary routing and hinge-applying apparatus, at proper locations along the jambs. These positions will be different because the top of the door for a left-opening door will be at the reverse end at the workstation than that for a right-opening door. There is therefore a need for more efficient mechanical dispensing and feeding devices for elongated articles.
This invention relates to a method and apparatus for dispensing and feeding to a workstation elongated articles which are vertically stackable and have a substantially common longitudinal dimension. It particularly concerns sequentially dispensing from separate dispensers onto a common pathway and feeding to the workstation along that pathway articles of different shape. In this invention articles of each shape are dispensed onto the pathway from a group of articles all having that shape in common and the articles dispensed from all the groups are fed sequentially along the common pathway in a downstream direction to the workstation. The dispensers are arranged in tandem in the pathway direction to the workstation and each is positioned above the pathway and oriented to dispense elongated articles with their longitudinal directions transverse to the pathway direction. Advantageously, the dispensers along the pathway may be positioned higher than the workstation and the pathway extending under them in the downstream direction to the location of the workstation provided with a downward slope steep enough that the articles dispensed onto the pathway from the dispensers will slide by gravity down the pathway to the location of the workstation.
As another feature of this invention, a receiver is provided at the end of the pathway at the workstation location for receiving articles dispensed onto and fed downstream on the pathway and feeding them sequentially from the pathway to the workstation. The receiver may take the form of an extension of the pathway that pivots from an upward receiving position, at which the article is received and retained thereon by a retainer desirably at its downstream margin, and a downward delivering position, at which the article is released from the retainer and deposited in a holder for the article at the workstation extending transversely of the downstream direction of the pathway.
As another feature of this invention an elongated article dispenser is provided that is comprised of opposed end supports, each for receiving and supporting a respective longitudinal end of elongated articles, which are stacked in a vertical stack on the dispenser, and sequentially dispensing the articles by simultaneously releasing the ends of the bottom article while continuing to support the ends of the articles remaining in the stack. Desirably, each end support has a stack guide for maintaining the articles in a vertical stacked condition. Each end support has a bottom article support for supporting the respective end of the bottom article stacked on the dispenser and a support for supporting the respective end of the next from the bottom article stacked on the dispenser. Both the bottom article supports and the next to bottom article supports are each operable between a support position and a release position for releasing their supported article ends to drop therebelow. To dispense an article, the bottom article supports of both end supports are simultaneously operated to release and thereby separately dispense the bottom article to the pathway below while the supports for both ends of the next to the bottom article maintain their support of that article and the articles stacked thereon. The bottom article supports are then returned to their support positions and the supports for the next to bottom article are simultaneously operated to their release positions to drop the next to bottom article to the bottom article position where the ends thereof are now supported by the bottom article supports. The next to bottom end supports may then be operated to support the ends of the next article in the stack, in preparation for the next dispensing cycle.
In yet another feature, the workstation elongated article holder comprises a clamp for securing the article along its elongated direction for work operations to be carried out against a selected longitudinal side of the article in which the clamp has a ram for urging against the longitudinal side of the article opposed to the selected side to secure the article against work forces acting against the selected side. The ram has a yieldable driver, such as one or more pressure-operated pistons, for yieldably urging the ram to its engaged position against the side of the article and a lock for mechanically fixing the ram in the engaged position to resist work forces against the selected side of the article. In this manner the article may be held in place by the ram with a moderate yieldable force, that will avoid damage to the article, and still be held at that position against the work forces by the greater resistance by the mechanical lock.